1. Security Design

2. Encryption
Encryption involves the use of secret keys (small binary files) to convert documents and communication channels into seeming random data, but losslessly convertible to the original if the key is known.
Encryption is necessary to send (and store) sensitive information.
There are two types of encryption algorithms for communication:
Symmetric Key Algorithms: Here both parties have a shared secret key, the data is encrypted, transmitted, and then decrypted by the other party.
Asymmetric (Public) Key Algorithms: Here a key is composed of two parts, a public key that is used to encrypt the data, and a private key that is used to decrypt the data. The sender encrypts the data with the receiver's public key and only the receiver (with their private key) can decrypt it.

3. Digital Certificates
Often symmetric (or private) keys are used to digitally 'sign' documents to demonstrate that they were created by the authorized sender. Such a digital signature often includes a timestamp and a hash of the original document to verify that no part of the document was modified.
Certificates can be issued by Certificate Authorities who confirm the identifies of the actors.

4. Database Survivability
A DBMS, in addition to making every effort, to prevent an attack, should do the following if an attack is detected.
Confinement: Eliminate an attacker's access to the system and contain the problem to prevent further spread.
Damage Assessment: Determine the extend of the problem, including failed functions and corrupted data.
Reconfiguration: Change options to allow the database to continue operating while recovery proceeds.
Repair: Recover lost or corrupted data and restore functionality.
Fault Treatment: Identify the weakness exploited by an attack and take steps to prevent reoccurrence.